Title: Development of a cryogenic hydrogen microjet for high-intensity, high-repetition rate experiments

Abstract

The advent of high-intensity, high-repetition-rate lasers has led to the need for replenishing targets of interest for high energy density sciences. We describe the design and characterization of a cryogenic microjet source, which can deliver a continuous stream of liquid hydrogen with a diameter of a few microns. The jet has been imaged at 1 μm resolution by shadowgraphy with a short pulse laser. In conclusion, the pointing stability has been measured at well below a mrad, for a stable free-standing filament of solid-density hydrogen.

@article{osti_1360156,
title = {Development of a cryogenic hydrogen microjet for high-intensity, high-repetition rate experiments},
author = {Kim, J. B. and Göde, S. and Glenzer, S. H.},
abstractNote = {The advent of high-intensity, high-repetition-rate lasers has led to the need for replenishing targets of interest for high energy density sciences. We describe the design and characterization of a cryogenic microjet source, which can deliver a continuous stream of liquid hydrogen with a diameter of a few microns. The jet has been imaged at 1 μm resolution by shadowgraphy with a short pulse laser. In conclusion, the pointing stability has been measured at well below a mrad, for a stable free-standing filament of solid-density hydrogen.},
doi = {10.1063/1.4961089},
journal = {Review of Scientific Instruments},
number = 11,
volume = 87,
place = {United States},
year = 2016,
month = 8
}

Solid state regenerative amplifiers have proved to be a reliable source for producing stable millijoule pulses as short as a few picoseconds at repetition rates ranging from a few hertz to several kilohertz. Here we report on the operation of a cw pumped Nd:YLF regenerative amplifier that uses a convex-concave design to optimize output energy and stability while minimizing the energy density on critical intracavity optical components. The amplifier yields stable 5-mJ 40-ps pulses at 700 Hz and has achieved 1-mJ output at a 3.5-kHz repetition rate. Results and analysis of the beam profile and contrast ratio for this systemmore » are also presented. Our results are contrasted to the general design consideration of regenerative amplifiers.« less

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